[src/trunk]: src/lib/librumpclient Since we ~never have a frame waiting on th...

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/5f26f2190866
branches:  trunk
changeset: 763025:5f26f2190866
user:      pooka <pooka%NetBSD.org@localhost>
date:      Tue Mar 08 15:55:12 2011 +0000

description:
Since we ~never have a frame waiting on the initial call to waitresp,
call kevent before readframe.  Doesn't really affect performance,
but makes ktraces shorter ;)

diffstat:

 lib/librumpclient/rumpclient.c |  63 ++++++++++++++++++++++++-----------------
 1 files changed, 37 insertions(+), 26 deletions(-)

diffs (91 lines):

diff -r b179469127f7 -r 5f26f2190866 lib/librumpclient/rumpclient.c
--- a/lib/librumpclient/rumpclient.c    Tue Mar 08 15:35:28 2011 +0000
+++ b/lib/librumpclient/rumpclient.c    Tue Mar 08 15:55:12 2011 +0000
@@ -1,4 +1,4 @@
-/*      $NetBSD: rumpclient.c,v 1.39 2011/03/08 15:34:37 pooka Exp $   */
+/*      $NetBSD: rumpclient.c,v 1.40 2011/03/08 15:55:12 pooka Exp $   */
 
 /*
  * Copyright (c) 2010, 2011 Antti Kantee.  All Rights Reserved.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: rumpclient.c,v 1.39 2011/03/08 15:34:37 pooka Exp $");
+__RCSID("$NetBSD: rumpclient.c,v 1.40 2011/03/08 15:55:12 pooka Exp $");
 
 #include <sys/param.h>
 #include <sys/event.h>
@@ -202,37 +202,48 @@
 
                        dosig = 0;
                        for (gotresp = 0; !gotresp; ) {
+                               /*
+                                * typically we don't have a frame waiting
+                                * when we come in here, so call kevent now
+                                */
+                               rv = host_kevent(kq, NULL, 0,
+                                   kev, __arraycount(kev), NULL);
+
+                               if (__predict_false(rv == -1)) {
+                                       goto activity;
+                               }
+
+                               /*
+                                * XXX: don't know how this can happen
+                                * (timeout cannot expire since there
+                                * isn't one), but it does happen.
+                                * treat it as an expectional condition
+                                * and go through tryread to determine
+                                * alive status.
+                                */
+                               if (__predict_false(rv == 0))
+                                       goto activity;
+
+                               for (i = 0; i < rv; i++) {
+                                       if (kev[i].filter == EVFILT_SIGNAL)
+                                               dosig++;
+                               }
+                               if (dosig)
+                                       goto cleanup;
+
+                               /*
+                                * ok, activity.  try to read a frame to
+                                * determine what happens next.
+                                */
+ activity:
                                switch (readframe(spc)) {
                                case 0:
-                                       rv = host_kevent(kq, NULL, 0,
-                                           kev, __arraycount(kev), NULL);
-
-                                       if (__predict_false(rv == -1)) {
-                                               goto cleanup;
-                                       }
-
-                                       /*
-                                        * XXX: don't know how this can
-                                        * happen (timeout cannot expire
-                                        * since there isn't one), but
-                                        * it does happen
-                                        */
-                                       if (__predict_false(rv == 0))
-                                               continue;
-
-                                       for (i = 0; i < rv; i++) {
-                                               if (kev[i].filter
-                                                   == EVFILT_SIGNAL)
-                                                       dosig++;
-                                       }
-                                       if (dosig)
-                                               goto cleanup;
-
                                        continue;
                                case -1:
                                        imalive = false;
                                        goto cleanup;
                                default:
+                                       /* case 1 */
                                        break;
                                }